Pneumatic suspension for safety helmet



Aug. 21, 1956 E. R. DYE 2,759,186

PNEUMATIC SUSPENSION FOR SAFETY HELMET Filed July 7, 1953 3 Sheets-Sheet l Aug. 21, 1956 E. R. DYE 2,759,186

PNEUMATIC SUSPENSION FUR SAFETY HELMET Filed July 7, 1953 3 Sheets-Sheet 2 I VENTOR.

(I 5 0/ 776 ys.

Aug. 21, 1956 E. R. DYE

PNEUMATIC SUSPENSION FOR SAFETY HELMET 3 Sheets-Sheet 3 Filed July '7, 1953 INVENTOR. M49? United States Patent C PNEUMATIC SUSPENSION FOR SAFETY HELMET Edward R. Dye, Orchard Park, N. Y., assignor to Cornell Aeronautical Laboratory, Inc., Buffalo, N. Y., a corporation of New York Application July 7, 1953, Serial No. 366,460

4 Claims. (Cl. 2-3) This invention relates to protective helmets and more particularly to a pneumatic suspension for such a helmet.

The type of helmet with which the invention is concerned is that which is worn by miners, construction workers and the like and generally comprises a relatively hard shell, the purpose being to protect the head of the worker against injury from falling objects and contacts with objects occasioned by low or restricted head room.

The principal object of the present invention is to provide a suspension for such a safety helmet which effectively protects the head of the wearer against blows to the helmet, particularly impact blows such as might be occasioned by an object falling on the helmet 'or movement of the helmet while worn into striking contact with some object.

Another object is to provide such a suspension which cushions the head against blows to the helmet in such manner that the force of the blow is not merely distributed over an area of the head but the energy of the blow is dissipated in large measure and not merely stored so that rebound forces are minimized.

A further object is to provide such a suspension which gives effective protection for the top and side portions of the head.

A further object is to provide such a suspension which is comfortable to the wearer and is adjustable to his desires.

' A further aim is to provide such a pneumatic suspension which can be readily inflated and deflated.

A further aim is to provide such a suspension which adds very little to the weight of the helmet per se, is simple in construction and inexpensive to manufacture, and durable.

Other objects and advantages of the invention will be apparent from the following description and drawings in which:

Fig. l is a bottom elevational view of a helmet equipped with a suspension embodying one form of my invention.

Fig. 2 is a vertical transverse sectional view thereof taken on line 22 in Fig. 1.

Fig. 3 is an enlarged fragmentary vertical transverse sectional view thereof taken on line 3-3 in Fig. 1.

Fig. 4 is an enlarged fragmentary horizontal. sectional view thereof taken on line 44 in Fig. 2.

Fig. 5 is a fragmentary vertical sectional view thereof taken on line 55 in Fig. 4.

Fig. 6 is a fragmentary elevational view of that face of the lower row of cells shown in Fig. 2 which face lies against the inner surface of the helmet, and also showing the air filling stem for this row of cells.

Fig. 7 is an enlarged cross-sectional view of the aforesaid filling stem taken on line 7--7 in Fig. 6.

Fig. 8 is an enlarged fragmentary longitudinal horizontal sectional view of the filling stem and showing the valve arranged therein.

Fig. 9 is a view similar to Fig. 8 but showing the filling stem and valve in vertical section, this view being taken on a reduced scale on line 9-9 in Fig. 7.

Fig. 10 is a fragmentary vertical sectional view of the upper central portion of a helmet and showing a different way of mounting the upper row of cells to the helmet than shown in Fig. 2.

Fig. 11 is a sectional view thereof, on a slightly enlarged scale, taken on line 11-41 in Fig. 10.

Fig. 12 is a fragmentary bottom elevational view, similar to Fig. 1, and showing a helmet equipped with a suspension embodying a modified form of my inventron.

Fig. 13 is a vertical cross sectional view thereof, on a reduced scale, the view being taken on line 13-13 in Fig. 12.

Fig. 14 is a fragmentary view similar to Fig. 6 and showing a modified shape of cells.

The safety helmet illustrated in Figs. 1 and 2 is representative of the type of helmet for which my suspension is suited. As shown such helmet is in the form of a shell having a cup-shaped crown portion 20 which covers the head of the wearer and a brim portion 21. The crown portion is shown as having three corrugations or ribs 22 which run in a fore-and-aft direction. The helmet may be made of any suitable metal or non-metal material depending upon the purpose for which worn. The helmet illustrated is intended to be made of a suitable rigid plastic material.

In accordance with my invention the interior of the crown portion 20 of the helmet is equipped with a suspension which is shown in Figs. 1 and 2 as comprising a lower row of pneumatic pillows indicated generally at 23 which encircle the head of the wearer at brow level, and an upper arrangement or row of pneumatic pillows indicated generally at 24 which engage the top portion of the head. The pillows 23 are adapted to accommodate blows to the helmet applied in a substantially horizontal direction and the pillows 24 resist blows applied in a substantially vertical direction.

The pillows are made of a flexible substantially inextensible material such as polyvinyl although any other suitable material may be employed. Polyvinyl material was selected as the preferred material of which to construct the pillows 23 and 24 because it possesses the ability to bond or weld with itself under heat and pressure, or, in other words, to be heat sealed. This facilitates the construction of the pillows.

Referring to Fig. 6, the row of pillows 23 is formed of two strips of polyvinyl sheet material joined together or heat sealed along their upper and lower margins, as indicated at 25 and 26 respectively, and also joined together or heat sealed in a transverse direction at intervals along their length, as indicated at 28, to thereby define a series of inflatable cells 29 each preferably of uniform size and of generally rectangular outline in plan. The sealed ends of the strips, indicated at 30 in Fig. 1, are preferably adjustably joined by reducing one in width and passing it through a slot in the other.

Each area or narrow band of transverse sealing indicated at 28 is interrupted at about its center, at the place indicated by 31 in Fig. 6, so as to leave a narrow portion of the plys unbonded and thereby provide a narrow passage 32 as shown in Fig. 2. Thus each cell 29 has an inner and outer wall 33 and 34 respectively (see Figs. 4 and 5), adjacent pillows being connected by webs provided by the sealing at 28 (see Fig. 2) and the interiors of all cells are in communication with one another through the interconnecting restricted passages 32.

Referring to Fig. 6, one of the pillows or cells 29 has a tubular stem 35 extending upwardly from the upper margin thereof for introducing and exhausting air from the cells to control the degree of inflation of the same. As shown the stem 35 is formed by integral extensions of the plies which form the pillow to which this stem is connected and heat sealing these extensions along their longitudinal meeting edges, as indicated at 36, so asto form a tubular stem.

While any suitable closure may be provided for the stem 35, that shown in Figs. 6-9' has been found particularly advantageous and comprises an internal check valveformed of polyvinyl sheet material. This valve consists of two superposed elongated sheets 3838 each of tapered outline and heat sealed along their meeting longitudinal edges as indicated at 39 so as to formnormally a flattened tube open at its opposite ends. This valve tube is arranged within the stem 35' adjacent the free end thereof, the narrow end of the valve tube being innermost and the broader end thereof being heat sealedto the mouth of the stem, as indicatedat 40-40. The thickness of the polyvinyl sheet material used for the valve tube is preferably thinner than that used for the stem 35, although this is not essential. For example, if the length of the stem 35 were made longer and tapered as shown in Fig. 6, the outer portion could be turned inwardly of the stem to provide the equivalent of the fabricated valve stem shown and this would eliminate the transverse heat sealing 4.0 at the mouth of the stern 35'- although such an arrangement would be more bulky at the stem mouth than the arrangement shown.

When air is introduced intothe stem 35 as by blowing into it by mouth, the air separates or spreads apart the walls 38 --38 along their central portions and form a passage through which the air flows into the stem 35 and thence into the cell 29 to which this stem is connected and into the other cells through the connecting passages 32'. Very little pressure need be maintained within the cells 29 to give satisfactory inflation for protective purposes, as more fully explained later herein, the pressure not exceeding in the order of one inch of water. When air ceases. to be forced through the dilated. valve, the walls 38 -38 thereof collapse against each other under the pressure of the air, confined withinthe cells and stem 35; This pressure effectively forces the walls 3838 against each other and it has been found to providean. effective self closing valve. It will be noted that the higher the pressure surrounding the valve walls 3838 the morethesewalls will: be forced against each other.

Should it; be desiredato deflate the cells 29, either com.- pletely or partially, this can. be readily achieved by in serting a suitable elongated object (not shown) such as a match. stick ornail into. the crevice of the valve so asv to. separate. the walls 3838 thereof. When thisis done,.

these walls will assume the position shown by broken linesv and:v represented by. the numeral 3-8'38f in Fig. 7.

escapes outwardly of the stem past the inserted object (not: shown). to. the atmosphere. In. this. manner the cells.2 9- can. be quickly and easily deflated to. the degree desired.

Referring-to Figs. 1, 2 and 4, the lower row ofpillows 2.3; is shownas arranged. within the, crown. portion 20* of the helmet; adjac nt the mouth thereof and extending the; full perimctcll thereof... In this embodiment the rowof pillows is; mounted onthe, helmet andv is: faced on. its head engaging side with a flexible sweat, band 40:1nade of; any! suitable material; such as leather, real: or imitation- The means for mounting the row of, pillows on; the, helmet comprises a strap 41; and button 42; as shown in. Eigs; 4. and 5. The strap 41. extends vertically over the; bulge of the; pillow and is heat sealed along its opposite. ends,to-thelongitudinal edges 25, 26 of the pillow. This. straphas a central hole 43 through which: the button 42 projects; The button is shown, as having a shanlc 44, an enlarged fiat head- 45erone end and a frusto-conical enlarged head 46wat' its opposite end. The flat head 45 lies between the outer wall: 34 and strap 41;, the shank 44; extends through the hole 4-3 in this strap and also. a. hole 48' in. the helmet; and the frusto-conical head 46' is arranged exteriorly of the helmet, the inwardly facing the buttons 42 are first arranged on the straps 41 and thereafter the frusto-conical heads 46 are pressed through the holes 48; in the helmet. suitable flexible resilient material so that the frusto-conical heads will compress to pass through the holes 48' and thereafter.- expand' into the locking condition. shown in Figs. 4 and 5.

Referring to Fig. 6} a strap 41 is shown as provided on every other cell 29. This is merely illustrative. A strap may be provided on every cell or fewer than the alternate ones shown, as desired.

The means for mounting the sweat band 40 on the row of pillows 23 include straps 49 on the pillows, a backing' 50' onthe sweat band and a band 51 laced between these straps and backing.

The straps 49 are similar to the straps 41 and are preferably provided on. every cell 29. Thus, referring to Figs. 4 and 5, each strap 49 extends over the bulge of its cell and is heat sealed at its opposite edges to the longitudinal edges 25, 26 of the pillow.

The backing 50: is inthe form of a band of substantially the same width as the sweat band 40- and lies against its inner face, being suitably secured thereto along its longitudinal edges as by rows of stitching 5252. Adjacent the vertical edges of each strap 49, the backing isprovided vertical slots 53 so as to leave a portion 54' intermediate these slots.

The band- 5-1 is laced between the sweat band 40 and backingSti, onthe one hand, and the strap 4-9 and outer wall 33 of the cell 29, on the other hand, the band 51 passing through the slots 53' as shown in Fig. 4. The. lacing band- 51 is substantially as wide as the spacing between the rowsv of stitching 52. In this manner the. sweat band is securely mounted on the row of pillows. 23 and will not slipvertically with respect to the same.

The pillows, indicated generally at 24, are arranged; against the inside surface of the crest or dome portion; ofithehelmet toprotect the top of the head of the wearer of the helmet. These pillowsware in the form of an. annulan row of cells- 55 each of isosceles. trapezoidal outline as viewed; in. Fig. 1. They are formed in thesame mantree as the=pillows 23-. Thatis, two sheets of polyvinyl? sheet material, each annular in form are heat sealed. along their meeting edges, as. indicated at 56, 5-8 and divided from; each other by radiating. bonded portions 59. The; portions 59 are interrupted to leave on unbonded portion 60 which provides a narrow passage 61 which connects adjacentzcellsSS. One of these cells along its outer edge formed with a filling stem. 62'. which is shown; as constructed similar to the filling stem 35 and. contains the same internal. check. valve previously described. In this connection, when the filling. stemsare not being used, the free: endxportionofi thefillingstem 62 is inserted behind the lower row of pillows 23. in the: space between adjacentcells therein', and-.thefilling stem. 35 is. inserted in the. space between adjacent cells 55 in the upper'row of pillows 24,

. maybeprovided, asdesired. The spider-framezis preferably made of a flexible sheet plastic material so that the The buttons are made of a" free ends of the arms 65 may be cemented or heat sealed to the outer flange 58 where it crosses the same, as shown at 66.

The central part 64 of the spider frame may be secured to the helmet in any suitable manner. As shown in Fig. 2, the central part 64 of the spider frame is held to the helmet by a screw 68 screwed into a threaded recess 69 provided in the central corrugation 22 of the helmet which corrugation has been filled in with material, preferably during its formation, to provide a body 70 in which the recess 69 may be formed.

Instead of filling in the central corrugation and tapping the hole 70 therein to receive the screw 68, the arrangement shown in Figs. and 11 may be employed. As there shown the central corrugation 22' has an enlarged groove 71 which is traversed by a bowed plate 72. The opposite ends of this plate 72 engage the side walls of the groove 71 and this plate is centrally provided with an opening and ofiset fingers 73-73 which are struck out from the body of the plate. These fingers form an interrupted female thread to receive the male thread on the screw 68. It will be seen that by tightening the screw 68 the upwardly bowed plate 72 will tend to flatten or straighten out which will force the ends of this plate into firmer engagement with the walls of the groove 71. If desired the ends of the plate 72 may be toothed or serrated to dig into the helmet and assure an even more positive anchorage.

It will be further noted that the spider frame, on which the upper row of pillows 24 is mounted, has its arms 65 lying against and conforming to the inner surface of the crown portion 20 of the helmet, as shown in Fig. 2. Because of the geometry of this row of pillows there is no need to secure the inner and upper flange thereof to the arms 65, although this may be done if desired.

A diiferent mode of attaching the rows of pillows 23' and 24 is illustrated in Figs. 12 and 13. As there shown a series of long strips 74 pass over the webs connecting adjacent cells in the lower and upper rows, each such strip being cemented to the portion of the helmet over which it extends and contacts, as best shown in Fig. 13. Inasmuch as the lower row of pillows 23' is shown as having more cells in it than the upper row, additional strips 75 may be employed between the longer strips to secure only the lower row of pillows to the helmet. The strips 75 are cemented to the helmet as in the case of the longer strips 74. This manner of mounting the upper and lower rows of pillows 23' and 24 is advantageous in that it requires less adaptation of the helmet and there are no holes required in the helmet to receive the buttons as in the case of the arrangement shown in Figs. 1-5. It will be noted that a sweat band is not shown in the construction shown in Figs. 12 and 13, the head of the wearer engaging directly with the inner side walls of the pillows or cells.

The contour of the pillows or cells may be of any suitable form other than as shown in Fig. 6. As an example, a circular form of pillow 76 is illustrated in Fig. 14. These may be formed from two sheets of heat scalable material, bonded together along marginal portions having their inner edges undulating. Thereafter the heat sealed margins may be trimmed leaving the flanges 78, 78. The portion indicated at 79 is unbonded and leaves a restricted passage connecting adjacent cells.

The cells or pillows are resistive to the displacement of air therefrom, the size of the passages therebetween serving as throttling orifices to dissipate energy absorbed by compression of any cell by the application of the impact force to the helmet from a direction which will tend to compress or flatten this particular cell.

It is to be noted that the annular row of cells 23 or 23' provides a pneumatic headband cushion in which the cells are so proportioned with the circumferential length of each cell being less than twice its height such that they present substantially their full areas on the inner side of the row for effective engagement with the wearers head at brow level and on the outer side of this row the cells present substantially their full areas for effective engagement with the helmet shell. Likewise, the annular row of. cells 24 or 24' is so proportioned as to present substantially the full area of each cell on opposite sides thereof for efiective engagement with the top of the head on the inner side of this row and the dome portion of the helmet shell on the outer side of this row. Since both rows of cells are adapted to be inflated by breath of mouth the cells may contain a low pressure. When the helmet receives an impact blow which tends to flatten those cells interposed between the shell and the wearers head generally in the line of force of such blow, the air within such interposed cells is compressed further without bottoming since the cells are dimensionally inextensible and the compressed air is throttled through the restricted passages connecting such interposed cells with other cells in the same row thereby to dissipate the energy of the impact blow. The increased pressure in the adjoining cells causes them to hug the head and distribute the impact of the blow over a large area. Thus the force of the impact is eflectively absorbed and distributed and rebound effects are dampened.

While the row of cells 23 or 23 encircling the head at brow level is essential, and it is also essential to provide a means for protecting the top of the head of the wearer, such means need not necessarily be of the pneumatic type illustrated by the cells 24 and 24 but may be a strap arrangement shown in my copending application Serial No. 254,757 filed November 3, 1951 and entitled Geodetic Strap Suspension for Helmets, now Patent No. 2,679,046 dated May 25, 1954.

I claim:

1. In a safety helmet having a shell including a cupshaped crown portion adapted to cover the head of the wearer, the combination therewith of a pneumatic headband cushion for supporting the helmet on the head of the wearer in spaced relation thereto and to protect the head from lateral impact blows against the helmet comprising an annular row of air cells made of a flexible substantially inextensible material and mounted within said crown portion of said shell adjacent the mouth thereof and extending the full perimeter thereof, means interconnecting said cells by restricted passages arranged between adjacent cells, said cells being so proportioned with the circumferential length of each cell being less than twice its height such that they present substantially their full areas on the inner side of said row for effective engagement with the wearers head at brow level and on the outer side of said row said cells present substantially their full areas for eflective engagement with said shell, and means for inflating said cells by breath of mouth, whereby said cells may contain a low pressure and, when the helmet receives a generally horizontally directed impact blow which tends to flatten those of said cells interposed between said shell and the wearers head generally in the line of force of such blow, the air within such interposed cells is compressed further without bottoming and the compressed air is throttled through the said restricted passages connecting such interposed cells with other of said cells thereby to dissipate the energy of the imp-act blow.

2. In a safety helmet having a shell including a cupshaped crown portion adapted to cover the head of the wearer, the combination therewith of a pneumatic headband cushion for supporting the helmet on the head of the wearer in spaced relation thereto and to protect the head from lateral impact blows against the helmet comprising a head encircling flexible sweat band, an annular row of air cells made of a flexible substantially inextensible material and arranged between said sweat band and said crown portion of said shell and extending the full perimeter thereof, means interconnecting said cells by restricted passages arranged between adjacent cells, said cells being so proportioned with the circumferential length of each cell being less than twice its height such that they present substantially their full areas on the sweat hand side thereof for effective, engagement with the wearers head at, brow level and on. the opposite side said cellspresenting substantially their full areas for effective engagement with said shell, and means for inflating said cells by breath of mouth, whereby said cellsmay contain a low pressure and, when the helmet receives a generally horizontally directed impact. blow which tends to flatten those of said' cells interposed between said shell and the wearers head gen erally in the line of force of such blow, the air within such interposed cells is compressed further without bottoming and the compressed air is throttled through the said restricted passages connecting such interposed cells with other. of said cells thereby to dissipate the energy of the impact blow.

3. In a safety helmet having a shell including a cupshaped" crown portion adapted to cover the head of the wearer,,the combination therewith of means for supporting the helmet on the head of the wearer in spaced relation thereto to protect the same from impact blows against the helmet, comprising a pneumatic headband cushion including an annular row of air cells made of a flexible substantially inextensible material and mounted within said crown portion of said shell adjacent the mouth thereof and extending the full perimeter thereof and adapted to encircle the head of the wearer at brow level and interconnected by restricted passages to control the flow of air between adjacent cells, a pneumatic crown cushion arranged within said crown portion at the dome thereof for engaging and protecting the top portion of' the wearers head including an annular row of air cells made of a flexible substantially inextensible material and interconnected by restricted passages to control the flow of air between ad'- jacent cells, the cells in each of said rows being so proportioned that the circumferential length of each cell is less than twice its height, and means for inflating both rows of said cells by breath of mouth, whereby the cells may contain a low pressure and, when the helmet receives an impact blow which tends to flatten those cells interposed between said shell and the wearers head generally in the line of force of such blow, the air within such interposed cells is compressed further without bottoming and the compressed air is throttled through the restricted passages connecting such interposed cells with other cells in the same row thereby to dissipate the energy of the impact blow.

4. In a safety helmet, means for pneumatically supporting the helmet on the head of a wearer in spaced relation thereto and to protect the head from impact blows against the helmet, comprising a pneumatic headband cushion including an annular row of air cells made of a flexible substantially inextensibl'e material and adapted to encircle the head, of the wearer at brow level and interconnected by restricted passages to control the flow of air between adjacent cells, a pneumatic crown cushion including another annular row of air cells made of a flexible substantially inextensible material, and arranged above said first row and adapted to engage and'protect the top portion of the. wearers head and interconnected by restricted passages to control the flow of'air between adjacent cells, the cells in. each ofsaid rows being so proportioned that the circumferential length of each cell is less than twice its height, means for inflating the cells in both rows by breath of mouth, whereby said cells may contain a low pressure and, when the helmet receives an impact blow which tends to flatten those cells interposed between the helmet and the wearers head generally in the line of force of such blow, the air within such interposed cells is compressed further without bottoming and the compressed air is throttled through the restricted passages connecting such interposed cells with other cells in the same row. thereby to dissi'patethe energy of the impact blow, means for mounting said headband cushion on said hehnet, and means for mounting said crown cushion on said helmet comprising a spider-like frame having a central part and arms radiating from said central part and connected at their outer ends to the outer edges of said crown cushion and a fastening securingrsaid central part to said helmet.

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